1. Field of the Invention
The present invention relates to a database representation technology and in particular to a method of representing a tree database in a display menu.
2. Description of the Related Art
FIG. 1 is a diagram of a tree database. The database name 10 of a tree database is the root node of the tree structure. The tree database includes several first level data nodes, such as Audio 12, Image 14, and video 16. The first level data node Audio 12 includes second level data nodes, i.e. Audio sub-folder 1, Audio sub-folder 2, and Audio sub-folder 3, as shown in FIG. 1, 18. Similarly, the first level data node Image 14 owns second level data nodes 20, Image sub-folder 1, Image sub-folder 2, and Image sub-folder 3. The first level data node Video 16 includes Video sub-folder 1, Video sub-folder 2, and Video sub-folder 3, as shown in FIG. 1, 22. The second level data node may be a null set. As an example, if the first level data node Audio 12 has a null set as its second level data node, then 18 is empty while Audio 12 still belongs to the first level data nodes. The tree database can be a general database or a directory system.
Presently, there are two methods of representing the mentioned tree database. The first representation method utilizes combo boxes. The second representation method utilizes combo boxes and tabs. FIG. 2 is a diagram of representing a tree database as combo boxes. The first level data nodes of a tree database are represented in a combo box 26. The second level data nodes are represented in a combo box 28. The combo boxes 26 and 28 are displayed in a display device for selection, as shown in FIG. 2, 24.
As an example, one of the first level data nodes of a tree database is represented in a combo box 26, and may be Video. The second level data nodes of Video 26 are represented as a combo box 28. The combo box 28 only displays one of the second level data nodes, such as Video sub-folder 1. If a cursor is moved to the right side of the combo box 28, i.e. a pop-up menu is displayed, and the remaining the second level Video data nodes will be displayed in the display device. If a cursor is moved over the pop-up menu of the combo box 26, the remaining first level data nodes of the tree database, such as Audio and Image will be displayed in the display device. Therefore, a tree database can be represented completely by combo boxes and displayed in a display device for selection by the described method.
There are, however, some disadvantages to the described representation method. Regarding selection, a user must select a desired first level data node and the second level data nodes included in the selected first level data node sequentially. If the desired nodes are located at different locations or the tree structure of the tree database is very complex, the user has to switch between the first and second level data nodes repeatedly.
The second representation method utilizes combo boxes and tabs to represent a tree database. FIG. 3 is a diagram of a tree database represented by combo boxes and tabs. The first level data nodes of a tree database are represented in tabs 32. The second level data nodes included in a first level data node are represented in a combo box 34. The tabs 32 and the combo box 34 are displayed in a display device for selection, as shown in FIG. 3, 30.
For explanation, the first level data nodes of a tree database, such as Video, Audio, and Image, are represented in tabs. If the first level Video data node is represented in tab 32, then the second level Video data nodes are represented in the combo box 34. Here, the combo box 34 only displays one of the second level data nodes of Video. If a cursor is moved over the pop-up menu of the combo box 34, then the rest of the second level data nodes of Video will be displayed in the display device. Other tabs are utilized to represent other first level data nodes, such as Audio or Image. If a cursor is moved on another tab, such as tab 2, the corresponding first level data node will be displayed in the display device. The second level data nodes included in the selected first level data node tab 2 will be represented in a combo box as mentioned. Thus, a tree database can be represented in combo boxes and tabs completely and displayed in a display device for selection.
There are, however, still some problems with the described representation method. For example, if the number of the first level data nodes is very large, then the method must utilize numerous tabs to represent the first level data nodes. However, only a few data nodes will be selected as working nodes, making display and utilization inconvenient. Furthermore, the numerous tabs of the first level data nodes will occupy excessive memory space of the user interface.